Heat control radiator valve



Oct. 2, 1934. c. A. DUNHAM 1,975,635

HEAT CONTROL RADIATOR VALVE Filed Nov. 11, 1929 2 Sheets-Sheet l u y lf 171118111661 LZy/Z Z Ail/1 I I a F c. A. DUNHAM 1,975,635

HEAT CONTROL RADIATOR VALVE Filed Nov. 11, 1929 2 Sheets-Sheet 2 U ITufen or. [/gy/b /zAJ mim ,if orngys.

My will N NM J N 7 v @N f; QM O 1 N mum w R M I w 7 g MM A NM v WM NM 4 QM. AA V .Wfi A J, Y a A r 4 L 1 O O W hw w K O N Q ///H//U//////// i vNnm .w r Q 1 i V Aw I \l H/ QFQ Patented Oct. 2, 1934 UNITED STATES HEAT CONTROL RADIATOR VALVE Clayton Ai'Dunham, Glencoe, 111., assignor to C. A. Dunham Company, Marshalltown,

a corporation of Iowa Iowa,

Application November 11, 1929, Serial No. 406,411

12 Claims.

This invention relates to new and useful improvements in heat control radiator valve, and more particularly to an improved form of inlet valve for controlling the fiow of steam to a radiator or group of radiators in a steam heating system.

It is a well known fact that the rate of steam flow through an orifice will depend upon the size of the orifice and also upon the pressure difference existing between the two sides of the orifice. With an orifice of constant size, the steam fiow may be increased by increasing the pressure difference between the two sides of the orifice. On the other hand, with a constant pressure difference existing between the two sides of the orifice, the steam fiow may beincreased by increasing the size of the orifice and decreased by decreasing the size of the orifice. In some systems of steam heating, a substantially fixed pressure difierence is maintained between the supply and return sides of a radiator or radiating unit, just sufficient to maintain the required fiow of steam into the radiator and to withdraw the non-condensible gases and condensates therefrom. The pressure of the steam supplied to the radiator may be atmospheric, or may be above or below atmospheric pressure, or the pressure maybe varied in accordance with the heat radiation desired, but the pressure in the return piping is 0 maintained lower than this supply pressure by a predetermined substantially constant amount. In such a'system, the relative rates of steam flow into the several radiators will depend upon the relative sizes of the supply piping, and upon the a relative sizes of any restricting orifices through flow in order to enter the respective radiators. It is desirable to maintain a proper balance in the supply system, that is mainmm a reservoir condition in the supply piping by keeping the velocity throughout the entire steam supply piping at relatively low values so as to secure a practically uniform pressure drop between the source of supply and each individual radiator. Since commercial pipe sizes vary by relatively large amounts it is difficult to properly select the supply piping so as to secure the desired balance, and accordingly orifice plates of proper size may be inserted in the piping in advance of each radiator or group of radiators to provide the proper balance in the system. The area of this orifice will depend upon the size or capacity of the radiator, and its position in the heating system. This principle has been used in the subwhich the steam must atmospheric heating systems covered ;by the patents grantedto Clayton A. Dunham, No.

1,644,114, dated October 4, 1927, and 1,706,401, dated March 26, 1929.

The present invention relates to improved means for increasing or decreasingthe quantity of heat or rate of steam flow to each .of the various radiators or radiating units, without otherwise disturbing the balance in the heating system. Frequently portions of a building are unoccupied and it is desirable to supply only suflicient heat to prevent them from reaching freez- M ing temperatures or temperatures that would 1 damage the water pipes and plumbing or other portions of the building. It may be desirable to cut down the heat supply to only a single radiator. or to a group of radiators in a zoning system. l0 Accordingly, the present invention provides improved means for varying the size of the orifice which controls the steam flow to each radiator or group of radiators, either above or below normal size, in accordance with the local heating Z6 conditions desired.

Furthermore, when a heating system is first installed the pipe lines contain considerable foreign material such as core sand which has not been entirely cleaned from the interior of the radiators, oil coatings which may have been placed within the pipes to prevent rusting during shipment and during the period that they are awaiting installation, and materials resulting from the packingused by the steam fitter to make tight 86 pipe joints, After a system has been in operation, it is frequently desirable to flush out each individual radiator and the piping system to carry away such foreign materials so that they may be finally emptied into the sewer. With 90 the usual type of inlet valve provided with a fixed regulating plate or orifice it is diflicult to accomplish this object. The present invention contemplates means for entirely removing the restricted orifice from the path of steam fiow under such conditions without removing or'dismantling the inlet valve.

More specifically, the present invention contemplates an inlet valve including a. normally closed main cut-01f valve, such valve being provided with a normally open auxiliary steam passage therethrough which serves as the restricting orifice. Means operable from outside the valve casing permit the enlargement or contraction of this orifice within certain limits so as to vary the rate of steam flow to the radiator. Means are also provided whereby an abnormal movement of this operating means will serve to open the normally closed main valve so that a free flow of steam or other fluid through thepiping system' may be permitted in order to flush out the system or for any other purpose.

The principal object of this invention is to provide an improved form of steam inlet valve such as briefly described hereinabove and disclosed more in detail in the specifications which follow.

Another object is to provide improved means whereby the heat supply to any individual radiator or group of radiators may be varied within predetermined limits.

Another object is to provide an improved inlet valve comprising a normally closed main valve and a normally open auxiliary steam passage, combined with means for alternatively varying the size of the auxiliary steam passage or opening the main valve. 1

Another object is to provide an improved form of indicating device positioned outside the valve casing for indicating the normal open position of the flow control members, and the amount of variation from this normal position to which the valve may be adjusted.

Another object is to provide improved means for adjusting the indicating apparatus after the valve has been installed in the system.

Another object is to provide an improved valve of the type hereinabove referred to, involving readily interchangeable thimbles whereby the normal opening of the orifice or steam passage may be varied in accordance with the positioning of the valve in the heating system or the size of the radiator supplied therethrough.

Another object is to provide improved means whereby the restricted fluid passage may be enlarged to permit the piping and radiating system to be flushed out. w

' Other objects and advantages of this invention will be apparent from the following detailed description of one approved form of apparatus capable of carrying out the principles of the invention.

In the accompanying drawings:

Fig. 1 is a plan view of the valve.

Fig. 2 is a longitudinal vertical section, taken substantially on the line 22 of Fig. 1.

Fig. 3 is a detail vertical section, taken substantially on the line 3-3 of Fig. 1.

Figs. 4, 5, 6, 7 and 8 are similar views showing in central vertical section a series of interchangeable thimbles designed for use in this valve.

Referring now to the drawings, the improved form of inlet valve will be described in detail. The valve casing 8 houses the main valve chamber 9 which is separated by internal web 10 through which is formed the main steam passage 11, from the inlet passage 12 in the downward extension 13 of casing 8, this extension being internally threadedat 14 to engage with the upper end of the supply pipe or riser through which steam is supplied to the radiator. The steam outlet passage 15 is contained in the lateral extension 16 of easing 8, and communicates with the nipple 17 which is externally threaded at 18 to be secured within the inlet opening of the radiator. An adjustable union between the nipple 17 and outlet extension 16 is provided by the collar 19 which is internally threaded at 20 to engage suitable threads formed on the outer end of extension 16, the collar 19 having an internally extending shoulder 21 adapted to engage behind an outwardly projecting annular shoulder 22 on the inner end portion of nipple 17. The inner end of nipple 23 fits adjustably within the outlet end of extension 16 thus providing a limited amount of angular adjustability to facilitate connecting up the valve with the riser and radiator. The upward extension 24 of casing 8 is externally threaded at 25 to engage similar internal threads in the bonnet 26.

The main valve member 27 will normally bev held down against the annular valve seat 28 formed on web 10 so as to close the main steam passage 11. Threaded at 29 into a central opening in valve member 27 is a thimble or bushing 30 having an auxiliary steam passage or orifice 31 formed therethrough. Thimble 30 may be provided with suitable notches 32 in its lower end for engagement with a tool whereby the thimble may be screwed into place or removed from the valve member 27. Thimble 30 is provided with an upwardly projecting sleeve portion 33 which may be externally beveled at 34. Thimble 30 may take a variety of forms and proportions, as shown for example in Figs. 4 to 3 inclusive, for reasons that will hereinafter be apparent. Main valve member 27 has an outer upwardly projecting sleeve portion 35 formed at its upper end with an outwardly extending annular shoulder 36. The closure member 37 has permanently secured thereto at its outer periphery a downwardly extending sleeve member 38 formed at its lower end with an inwardly extending collar or flange 39 adapted to slidably engage around the main valve member 2'7 beneath the shoulder 36 thereon. Closure member 37 is imperforate, but sleeve 38 is provided with a circumferential series of ports or openings 40 for permitting the flow of steam therethrough. An inner annular sleeve 41 projects downwardly from closure member 37 so as to telescope down 110 around the upwardly projecting discharge sleeve 33 on thimble 30. A compression spring 42 is confined between the upper surface of valve member 27 and the top of an annular groove formed in the lower surface of closure member 37. The compressed spring 42 serves to normally hold valve member 27 against the valve seat 28 in all normal positions of vertical adjustment of closure member 37.

It will now be apparent that the steam flowing 120 in through inlet passage 12 and the auxiliary steam passage 31 in thimble 30, must flow around through the annular passage formed between the sleeve members 33 and 41 on the thimble and closure respectively and thence out through ports 40 into the main valve chamber 9 from which it passes through outlet passage 15 and nipple 17 into the radiator. With a substantially constant pressure difference between the inlet and outlet sides of the valve, the rate of steam flow and consequently the volume of steam passing through the valve into the radiator will be determined by the size of the restricted orifice formed by the circuitous passage just described. By lowering the closure member 3'7, the annular passage between the sleeves 33 and 41 will be decreased in area and the eflective size of the orifice will be restricted. Conversely, by elevating the closure member 37 the efiective size of the orifice will be enlarged. In addition to this range of adjustability provided by the raising or lowering of closure member 3'7, the normal rate of steam flow may be changed by varying the size of the auxiliary passage 31, and the proportions of the sleeve member 33 in thimble 30. As already noted, Figs. 4 to 8 inclusive illustrate several a1- temative forms of thimble 30 that may be interchangeably positioned in the valve member 27. Fig. 4 illustratesa thimble 30* having a relatively small steam passage 31 and a relatively thick 150 requiring a large inflow of steam to replace the bonnet 26. An externally threaded nut 57 is enample in 'Figs. 4 to 8 inclusive.

steam condensed therein. In a similar manner, Figs. 5, 6 and '7 show intermediate forms of thimbles adapted for radiators of intermediate size. It will now be seen that all other members of the valve structure may be made of standard size and proportions, and that by inserting the proper thimble 30 the valve may be adapted for use with any standard size or type of radiator. -Obviously, there may be a great many more sizes of thimbles 30 provided than those shown by way of exproper thimble 30 for use in the valve, the approximately correct normal steam flow may be obtained, and any necessary finer adjustment may be obtained by a proper setting of the adjustable valve mechanism as hereinafter described.

A flexible corrugated sealing diaphragm or packing 43 is sealed at its lower end 44 to the outer upper edge of closure member 3'7, and at its upper end has an outwardly extending flange or ring 45 which is clamped between the upper edge of the ring extension 46 of casing 8 and the outer edge portion of the guide plate 4'7 which is held down by the annular shoulder 48 formed in bonnet 46. This flexible diaphragm member 43 forms, with the closure 3'7, a continuous imperforate upper wall for Valve chamber 9 to prevent the escape of steam through the top of the valve chamber without interfering with the requisite vertical movements of the movable valve members and the operating mechanism therefor. The particular form of sealing diaphragm 43 here illustrated, is disclosed more in detail and claimed in the copending application of Brennan and Wilding, Serial No. 412,861 filed December 9, 1929, now Patent No. 1,830,780, granted November 10, 1931.

The ring extension 46 might be formed as an integral part of valve casing 8, but is'here shown as a separate member in order that valve casings of standard type already in use may be adapted for this new valve by merely adding the extension ring 46 whereby the necessary additional upward movement of the valve mechanism is permitted.

The valve stem 49 is provided at its lower end with a head 50 which is swiveled within a recess 51 formed in the central top portion of cover 3'7 and held in place by the flange 52 which is spun inwardly over the head 50. The upper portion 53 of valve stem 49 has flattened sides or is of other non-circular form, and is vertically slidable through a passage 54 of similar contour formed in the guide plate 4'7 whereby valve stem 49 is held against rotation without interfering with its vertical movements. An internally threaded nut 55 is positioned above the guide plate 47 and is held in place by means of an outwardly extending annular flange 56 at its lower end engaging a similar shaped groove formed in gaged within the threads formed in nut 55, this nut 5'7 being formed with'a T slot 58 in which is engaged the correspondingly shaped head 59 on valve stem 49, whereby the valve stem and nut 57 are coupled together without capacity for relative rotativemovements. Either single or multi- By selecting the large pitch so that a comparatively small rotative movement of nut 55 will produce a comparatively large vertical movement of the non-rotatable nut 57. It will now be apparent that as the nut 55 is rotated or oscillated, the internal valve members 3'7 and 2'7 will be raised or lowered by means of the nut 5'7 and valve stem 49.

The nut 55 is provided with a circumferential series of external vertically extending teeth 60 (see Fig. 2) which are interengaged with a corresponding internal set of vertical teeth formed in the ring or operating head 62 which surrounds the nut 55. The ring or head 62 is normally secured in place about the nut 55 by means of a locking screw 63 extending through the head into an annular groove 64 formed externally in the nut 55. It will be apparent that by unscrewing the locking screw 63 the head or ring 62 may be elevated with respect to nut 55, 60 sliding over one another so that the nut and ring will still remain locked together for simultaneous rotative movements. v

A laterally projecting operating handle 65 of any suitable type is secured to operating head 62. An annular-dial plate 66, in the form of a split metal ring, is adapted to be sprung into place in a groove 67 formed in the top portion of bonnet 26. Different positions on this dial are suitably marked 'as by Normal, Warmer, and Cooler, and a pointer or indicating device 68 formed on ring 62, preferably at the side opposite the handle 65, is adapted to cooperate with these indications on dial 66' in order to show the position of the movable valve members. A stop pin or stud 69 is anchored in dial plate 66 at a point adjacent the Warmer" designation, preferably by having its lower end riveted through the plate as indicated at '70 in Fig. 4. The upper surface of bonnet 26 is formed with an annular series of spaced depressions '71, into any one of which the lower end '70 of this stop member may be in- I pointer or indicating finger 68 is adapted to engage the stop 69 to prevent further rotative adjustment of the operating mechanism in this direction when the closure member 3'7 has been lifted to the maximum extent permitted without lifting the main valve 2'7 from its seat 28. A closure plate '72 is adapted to be seated in the upper surface of ring or head 62, and this closure plate may-serve. as a name plate or carry other inscriptions. A stop shoulder '73 formed on valve stem 49 is adapted to engage the under surface of guide plate 4'7 before nut/5'7 engages the closure plate '72, to prevent forcing this closure plate from its seat.

When properly installed, ble 30 will be so selected, and the'indicating dial 66 will be so adjusted, that when the pointer or finger 68 is opposite the Normal indication on the dial the closure member 37 will'be at a midposition of vertical adjustment, and the size or :1;

tially the same as the open inlet valve and orifice plate disclosed in the Dunham patents hereinabove referred to. Now if it is desired to decrease the flow of steam into the radiator and thereby "cut down its heating effect, it is merely necessary to rotate handle 65 in a clockwise direction 1 the bushing or thimthe teeth 7 (Fig. 1) so as to move the finger 68 toward the Cooler indication, thus lowering the closure member 37 and decreasing the size of the steam orifice through the valve. This movement may be continued if desired until the sleeve members 33 and 41 completely telescope over one another so as to substantially cut off the flow of steam through the valve.

On the other hand, if more heat is desired, the handle 65 is rotated in a counter clockwise direction so as to move the finger 68 toward the Warmer indication thus increasing the size of the steam orifice and permitting a greater flow of steam into the radiator. Under normal conditions, all the steam that the radiator can condense should be permitted to fiow through the valve when the valve is set at Normal, but unusual temperature conditions or an unbalanced condition in the heating system may necessitate the movement of the valve control member toward Warmer in order to permit an increase in the steam fiow into the radiator. The finger or pointer 68 will engage the stop pin 69 before the overlapping flanges 39 and 36 on the relatively movable valve members have come into engagement, thereby preventing the lifting of main valve member 27 from its seat 28.

In case it is desired to open the main steam passage 11 so as to permit the piping system and valve to be flushed out, the locking screw 63 is unscrewed so as to permit the operating ring or head 62 to be elevated sufficiently to free the finger 68 from engagement with stop pin 69 so that the operating handle may be rotated further in a counter clockwise direction (Fig. 1), whereupon the flange 39 on closure 3'7 will'engage under the outstanding flange 36 on flange member 27 and lift this valve from its valve seat 28, thus opening the main steam passage 11 through the valve. After the system has been flushed out, the valve ports may be returned to their normal positions by a mere reversal of the steps just set forth.

It will now be apparent that a heating system of the type first set forth hereinabove will operate in the usual manner with all of these valves set at Normal, the heat output of the several radiators being regulated by changing the subatmospheric pressure of the steam supplied throughout the system. If, through faulty installation, or for any other reasons an unbalanced condition, exists in any portion of the radiating system, this may be corrected by a simple adjustment of one or more of the several inlet valves so as to slightly increase or decrease the rate of steam flow to the respective radiators. If, under special conditions, it is found desirable to more radically change the heat output of any radiator or group of radiators, this may be accomplished by a suitable adjustment of the valve handle 65. If for example a certain room or group of rooms is to be unoccupied so that it is unnecessary tokeep these rooms heated up to a normal temperature, the valve members may be adjusted so as to permit only a limited flow of steam to the radiators just suflicient to prevent a dangerously low .temperautre from being reached in these rooms.

While this improved valve member has been especially designed for use in a sub-atmospheric heating system, it will function in substantially the same manner in a heating system using steam at atmospheric pressure or at pressures above atmospheric. As long as a substantially constant pressure difierence is maintained between the inlet and outlet sides of the valve, the rate of steam flow through the valve may be varied by the proper adjustment of the effective size of the steam passage or orifice in the valve.

Instead of, or in addition to, the use of one of these valves at the inlet of each radiator in the system, a control valve of this type could be used before a group of radiators, or a branch of the radiating system as in a zoning system where difierent temperatures or heat outputs are to be simultaneously maintained in different portions of a building. In such case, the valve will function to regulate or adjust the steam fiow to the group of radiators or a zone in the same manner as hereinabove described in connection with a single radiator.

I claim:

1. In a steam heating system, an inlet valve comprising a valve casing provided with inlet and outlet openings and a main steam passage intermediate said openings, a valve seat surrounding said passage, a main valve member normally engaging the valve seat, said valve member having a normally open flow control passage therethrough, and; means operable from outside the casing for increasing or decreasing the effective size of this flow control passage, or for lifting the main valve from its seat to open the main steam passage, and stop means for normally limiting the movement of this latter operating means so that the main valve will remain closed.

2. In a steam heatmg system, an inlet valve comprising a valve casing having inlet and outlet openings and a main steam passage therebetween, a normally closed main valve controlling this passage, a normally open auxiliary steam passage in the main valve and means for variably controlling the fiow of steam through the auxiliary passage and for opening the main valve including an operating handle positioned outside the easing, a pointer on the handle, a dial mounted on the casing and cooperating with the pointer to indicate the normal position of the valve mechanism and the amount of adjustment from this normal position and means for adjusting the position of the dial on the casing.

3. In a steam heating system, an inlet valve comprising a valve casing having inlet and outlet openings and a main steam passage therebetween, a normally closed main valve controlling this passage, a normally open auxiliary steam passage in the main valve and means for variably controlling the flow of steam through the auxiliary passage and for opening the main valve including an operating handle positioned outside the casing, a pointer on the handle, a dial mounted on the casing and cooperating with the pointer to indicate the normal position of the valve mechanism and the amount of adjustment from this normal position, a stop carried by the dial in position to be engaged by the pointer when the auxiliary passage has been increased to its maxi mum opening, and means for moving the pointer out of engagement with the stop so that a com tinued movement of the handle may be utilized to open the main valve.

4. In a steam heating system, an inlet valve comprising a valve casing having inlet and outlet openings and a main steam passage therebetween, a normally closed main-valve controlling a handle keyed to the rotary member to impart rotation thereto, a pointer on the handle, a dial fixed to the casing and cooperating with the pointer to indicate the position of adjustment of the valve mechanism, a stop on the dial engaged by the pointer when the auxiliary passage has been increased to its maximum opening, the handle and pointer being slidable on the rotary member away from the casing to move the pointer out of engagement with the stop whereby further rotation of the handle and rotary member will open the main valve. 7

5. In a steam heating system, an inlet valve comprising a. valve casing having inlet and outlet openings and a main steam passage therebetween, a normally closed main valve controlling this passage, a normally open auxiliary steam passage in the main valve and means for variably controlling the flow of steam through the auxiliary passage and for opening the main valve including an operating handle positioned outside the casing, a pointer on the handle, an annular dial plate mounted on the casing and cooperating with the pointer to indicate the normal position of the valve mechanism and the amount of adjustment from this normal position, a stop pin fixed in the dial plate and having portions pro- J'ecting above and below the plate, the pointer engaging the upper portion of the pin when the auxiliary passage has been increased to its maximum opening, there being a series of spaced sockets in the valve casing beneath the dial plate to be alternatively engaged by the lower portion of the stop pin to lock the dial plate in adjusted position on the casing.

6. In a steam heating system, an inlet valve comprising a valve casing provided with inlet and outlet openings and a main steam passage intermediate said openings, a valve seat surrounding said passage, means cooperating with said valve seat to close said steam passage comprising a main valve member engaging the seat and having an auxiliary steam passage therethrough, a cupped closure member movable over said main valve member and having a steam passage leading thereinto, and cooperating flow control devices on the valve member and closure member to determine the steam flow through the members as the devices are moved toward or from one another, and means operable from outside the casing'for moving the closure member toward or from the valve member.

'7. In a steam heating system, an inlet valve comprising a valve casing provided with inlet and outlet openings and a main steam passage intermediate said openings, a valve seat surrounding said passage, means cooperating with said valve seat to close said steam passage comprising a main valve member engaging the seat and having an auxiliary steam passage therethrough, a cupped closure member telescopically engaging the main valve member and movable toward or from the valve seat, an expansion spring interposed between the closure member and valve member to normally hold the valve member against the valve seat, interengaging shoulders on the closure and valve members whereby the valve member will be lifted from its seat when the closure member is moved away from the seat more than a predetermined distance, there being steam passages leading into the closure member and cooperating flow control devices on the closure member and valve member to determine the steam flow through the members as the devices are moved toward or from one another and means operable from outside the valve casing for moving the closure member toward or from the valve seat..

'8. In a steam heating system, an inlet valve comprising a valve casing provided with inlet and outlet openings and a main steam passage intermediate said openings, a valve seat surrounding said passage, means cooperating with said valve seat to close said steam passage comprising a main valve member engaging the seat and having an auxiliary steam passage therethrough, a

, cupped closure member telescopically engaging the main valve member and movable towardor from the valve seat, an expansion spring interposed between the closure member and valve member to normally hold the valve member I against the valve seat, interengaging shoulders on the closure and valve members whereby the valve member will be lifted from its seat when the closure member is moved away from, the seat more than a predetermined distance, there being steam passages leading into the closure member and cooperating fiow control devices on the closure member and valve member to determine the steam flow through the members as the devices are moved toward or from one another, said devices including a thirnble fitted within the valve member and in which the auxiliary passage is formed, and a cooperating sleeve on the closure adapted to telescopically engage the thimble, and means operable from outside the valve casing for moving the closure member toward or from the valve seat.

9.;In a steam heating system, an inlet valve comprising a valve casing provided with inlet and outlet openings and a main steam passage intermediate said openings, a valve seat surrounding said passage, means cooperating with said valve seat to close said steam passage comprising a main valve member engaging the seat and having an auxiliary steam passage therethrough, a cupped closure member telescopically engaging the main valve member and movable toward or from the valve seat, an expansion spring interposed between the closure member and valve member to normally hold the valve member against the valve seat, interengaging shoulders on the closure and valve members whereby the valve member will be lifted from its seat when the closure member is moved away from the seat more than a predetermined distance, there being steam passages leading into the closure member and cooperating flow control devices on the closure member and valve member to determine the steam flow through the members as the devices are moved toward or from one another, said devices including a plurality of thimbles alternatively engageable within the valve member, auxiliary steam passages of diiierent sizes being formed in the respective thimbles, and a cooperating sleeve in the closure member adapted to telescopically engage the thimble, and means operable from outside the valve casing for moving the closure member toward or from the valve seat.

10. In a steam heating system, an inlet valve comprising a valve casing provided with inlet and outlet openings and a main steam passage intermediate said openings, a valve seat surrounding said passage, means cooperating with said valve seat to close said steam passage comprising a main valve member engaging the seat and having an auxiliary steam passage therethrough, spring means for normally holding the main valve closed, a movable closure having lost motion connections with the main valve member whereby opening movement of the movable closure beyond a predetermined normal range of movement will open the main valve in opposition to the spring means, means operable from outside the casing for moving the closure member, and cooperating flow control devices on the main valve member and closure member to determine the steam flow through the auxiliary steam passage as the closure member is moved through the normal range of movement.

11. In a steam heating system, an inlet valve comprising a valve casing provided with inlet and outlet openings and a main steam passage intermediate said openings, a valve seat surrounding said passage, means cooperating with said valve seat to close said steam passage comprising a main valve member engaging the seat and having an auxiliary steam passage therethrough, spring means for normally holding the main valve closed, a movable closure having lost motion connections with the main valve member whereby opening movement of the movable closure beyond a predetermined normal range of movement will open the main valve in opposition to the spring means, means operable from outside the casing for moving the closure member, cooperating flow control devices on the main valve member and closure member to determine the steam flow through the auxiliary steam passage as the closure member is moved through the normal range of movement, said devices including a thimble fitted within the main valve member and in which the auxiliary passage is formed, and a cooperating sleeve on the closure member adapted to telescopically engage the thimble.

12. In a steam heating system, an inlet valve comprising a valve casing providedwith inlet and outlet openings and a main steam passage intermediate said openings, a valve seat surrounding said passage, means cooperating with said valve seat to close said'steam passage comprising a main valve member engaging the seat and having an auxiliary steam passage therethrough, spring means for normally holding the main valve closed, a movable closure having lost motion connections with the main valve member whereby opening movement of the movable closure beyond a predetermined normal range of movement will open the main valve in opposition to the spring means, means operable from outside the casing for moving the closure member, and cooperating flow control devices on the main valve member and closure member to determine the steam fiow through the auxiliary steam passage as the closure member is moved through the normal range of movement, said devices including a thimble removably engaged within the main valve member, the thimble being formed with a steam passage therethrough of a size to determine the normal rate of steam fiow through the valve, and 

